1. Field
The present specification generally relates to optical fibers and, more specifically, to methods for making optical fiber preforms utilizing glass soot.
2. Technical Background
The cladding portion of an optical fiber preform may be formed by depositing glass soot onto a target, such as a glass core cane or glass cylinder, with an outside vapor deposition (OVD) process, a modified chemical vapor deposition process (MCVD) or an axial vapor deposition (AVD) process. For example, the glass soot may be generated by the pyrolysis of silicon tetrachloride, octamethyltetrasiloxane or a similar vapor phase precursor material. These deposition processes are highly optimized, high yield manufacturing processes. However, the formation of the cladding layer is often the rate limiting step in maximizing optical fiber output. Further, less than 100% of the pyrolysis product of the octamethyltetrasiloxane feedstock is deposited on the target during deposition of the cladding portion of the optical fiber preform. The remaining pyrolysis product of the octamethyltetrasiloxane feedstock is collected in a baghouse as relatively high purity silica glass soot.
In order to further improve optical fiber output and reduce raw material costs, alternative methods of forming the cladding portions of optical fibers are needed.